Ferroelectric RAM (F-RAM) Hits the Market With Infineon’s EXCELON Family

Infineon recently released its EXCELON family of ferroelectric RAM (F-RAM) memory devices. At the time of the announcement, the EXCELON family featured the highest-density serial F-RAM available in a commercial setting.

 

Infineon's EXCELON F-RAM chip, shown in a 24-ball FBGA package. Image used courtesy of Infineon

 

Despite its commercial availability, F-RAM is still a relatively new technology. In this article, we'll take a deeper look at F-RAM alongside its advantages compared to volatile and non-volatile memories. Finally, we'll review some target use cases for EXCELON F-RAM to highlight the family’s potential benefits for designers.

 

The Backbone of F-RAM

F-RAM is based on lead zirconate titanate (PZT), which exhibits interesting ferroelectric properties when placed in thin films. If a sufficiently high field is applied to ferroelectric materials like PZT, the material will retain some of its polarization after removing the external field. If the applied field is reversed, the polarization may be reversed accordingly.

 

Ferroelectric hysteresis loop with an applied field on the x-axis and polarization on the y-axis. After charging with a high E-field, the material retains polarization even with no applied field. Image used courtesy of Cadence

 

This shift in polarization can drastically change the material’s electric properties, making it suitable for various applications ranging from analog computing to non-volatile memory. In the latter case, since the internal polarization field can sustain itself without an outside source, it makes an excellent candidate for memory solutions where the memory must hold its preprogrammed values following a loss in power.

Compared to other forms of non-volatile memory, F-RAM has its own set of advantages. Some of the key advantages are its fast write speed, high performance, endurance to many write cycles, and high energy efficiency compared to EEPROM.

 

EXCELON: Making the Switch to F-RAM Simple

Throwing its hat into the F-RAM ring, Infineon developed the EXCELON family to maximize the performance of commercial F-RAM. Ranging in densities from 2–16 Mbit, the EXCELON family gives designers plenty of flexibility to accommodate F-RAM in their designs. This, combined with the 70x current reduction compared to existing F-RAM technology, make large-scale deployment of the EXCELON family easier on designers.

 

Block diagram of the EXCELON Ultra F-RAM memory. Image used courtesy of Infineon

 

According to the datasheet of one EXCELON device, Infineon's F-RAM devices can support a wide voltage range from 1.8–3.6 V and support the same interfaces and timings as traditional memories, making the switch to EXCELON F-RAM as easy as possible. In addition, the “instant-write” capabilities combined with the non-volatility of F-RAM ensures that no data is lost if power is removed in the middle of a write cycle. 

 

F-RAM’s Place in the Memory Industry

According to Infineon, the EXCELON F-RAM family was designed for the harsh data-logging requirements of automotive and industrial settings, where data loss could be devastating. The family is also built for life-enhancing patient monitoring devices, where access to data can literally be a life-or-death scenario.

One major advantage of F-RAM is its ability to capture data quickly and efficiently, especially in environments where reliable data is critical to functionality. In addition, the low-power nature of F-RAM makes it a valuable tool for designers looking to maximize the energy efficiency of a design.

Although F-RAM technology is still quite new, the trend toward high-efficiency ferroelectric devices benefits any design reliant on memory. F-RAM's robustness against power loss and improved efficiency and latency make it a promising innovation that may indicate more improvements to memory technology to come.

 

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Featured image (modified) used courtesy of Infineon.